We're meeting in Phoenix. In August. Let's face it, it's going to be hot. We encourage you to plan appropriately and to dress casually so that you are comfortable. 
Please take the heat seriously - Maricopa Country Heat Alert. If you're planning any outdoor activities, it's probably best to do them in the morning and/or evening when it is a bit cooler and the sun is not so strong. Always bring water with you outdoors and wear sunscreen.